Magnetic ejector and de-magnetizer



y 8, 1956 A. A. AMBROSE 2,745,043

MAGNETIC EIJECTOR AND DIS-MAGNETIZER Filed Dec. 29, 1955 '0 IN I "EN TOR.

ANTHONY A. AMBROSE BY 7 g *7 g 22 3 I2 22 ATTORNEYS United tates atent MAGNETIC EJECTGR AYD DE-MAGNETIZER Anthony A. Ambrose, Chicago, Ill.

Application December 29, 1953, Serial No. 401,020

11 Claims. (Cl. 317-123) This invention relates to a magnetic unit for use as a de-magnetizer and magnetic ejector, and in particular relates to a coil unit specifically designed and constructed to operate as a de-magnetizer and magnetic ejector.

There are many instances in the industry where it is desired to de-magnetize work members which may have become accidentally magnetized in the course of their manufacture, and which must be completely de-magnetized before being completed.

Ordinarily, such work members are de-magnetized either by passing them through an alternating magnetic field or by placing them in an alternating magnetic field and permitting the field gradually to diminish in strength.

' In either case, this operation is time-consuming and no practical way exists of doing the job rapidly.

In dealing with this problem I have discovered a 0011 construction and design which will not only accomplish rapidly and effectively the de-magnetizing of work members, but will also propel the work members through the coil when they are brought to one end of the energizing coil. I have found it possible to generate a high propulsive force in this manner, and the exact amount of the force can be regulated by the size of the coil employed and the amount of current which is passed through the coil.

Having the foregoing in mind, a primary object of the present invention is the provision of an electric coil capable of de-magnetizing magnetic work members introduced thereto.

Another object of this invention is the provision of an electric coil capable of exerting a unidirectional propulsive force on a plunger or work member introduced therein at one end of the coil.

A still further object of this invention is the provision of a de-magnetizing coil which will eject work members introduced thereto simultaneously with the de-magnetization thereof.

These and other objects and advantages of the present invention will become more apparent upon reference to the following specification, taken in connection with the accompanying drawings, wherein:

Figure 1 is a perspective view showing a de-magnetizing coil according to my invention;

Figure 2 is a vertical section through the coil indicated on line 22 of Figure 1;

Figure 3 is a vertical sectional view like Figure 2 but showing a slightly curved coil;

Figure 4 is a diagrammatic view showing how a plurality of the coils, according to my invention, might be arranged in series; and

Figure 5 is a sectional view showing a coil similar to the one illustrated in Figure 2, except for having a shell surrounding the unit.

Referring to the drawings somewhat more in detail, and in particular to Figure 2, the unit comprises a member which is of non-magnetic material and which is non-conductive. Member 10, which may also serve as a form over which coil 12 is Wound, may advantageously consist of a ice plastic or ceramic material, or of a resin bonded glass fiber or the like. The coil 12 is wound, as indicated at 12 in Figure 2, so as to have a conical recess 14 in the end thereof opposite member 10. Located within this conical recess is a ring 16 of highly electrically conductive material, such as copper. On the axis of the coil there is arranged a tube 18 which may be of brass or ceramic, and through which the work members being operated will pass, or within which a plunger that is operated by the unit is reciprocable. A layer of insulating material 20 separates tube 18 from ring 16, and ring 16 from coil 12, and also extends across the ends of the unit.

While the general arrangement illustrated in Figure 2 exhibits the characteristics of exerting a propelling force on a plunger or magnetic member, as introduced into tube 18 from the right end of Figure 2, still other proportions for the individual parts of the unit could be employed.

One particular arrangement which I have found particularly suitable has the ring member 16 extending along three-fourths of the length of the unit. In operation, the coil 12 is energized with alternating current and a magnetic work member placed at the right end of tube 18 will be drawn inwardly of the tube by the field set up by coil 12. This member will become magnetized and, because of its momentum, will pass into the portion of tube 18 that is surrounded by ring 16. In this latter portion of the tube 18 the Work member comes under the influence of the field from the induced current in ring 16, and a thrust is thus developed on the member that will drive it on through the tube 18 and out the left end thereof as it is viewed in Figure 2.

Where the coil is used for actuating plungers, the plunger can be from one-fourth to four times the length of the coil and will still be thrust through the coil in the one direction. Such a plunger would preferably be hard steel although a soft iron plunger could be employed, but is not as dependable in operation as a hard plunger.

In utilizing the coil for de-magnetizing work members, the size of the tube 18 and the size of the coil 12 would be determined by the average size of the work member to be passed through the coil.

The units may be arranged in multiple end to end, and for this purpose there may be provided the aligning pins 22 that will hold the coils in alignment with the tube 18 exactly in register.

For certain purposes it may be desirable for the passage through the coil to be arcuate, and for this purpose the arrangement of Figure 3 could be employed for all parts of assembly or somewhat modified so that the bore through the center tube is curved, as indicated at 24.

Inasmuch as the unit develops unidirectional thrust on a magnetic member passing therethrough, a number of the units 26 can be arranged in series, as in Figure 4. and clamped together between the end rings 28 by through-bolts 30, and articles propelled through the assembly at extremely high speeds. Such an arrangement could be utilized as a small or medium arm for throwing projectiles. It is believed that a unit large enough to be used as a mortar could be provided in this manner.

Normally, the coils of the several units 26 in Figure 4 would be energized by connecting them in parallel across a source of alternating current 32 so that, upon closing switch 34, all of the coils would be energized simultaneously. It might occur, however, that it would be desirable to have the coils slightly out of phase to increase the propulsive effort exerted on a member passing therethrough, and if such were the case it could be accomplished by including in the individual coil circuits impedances as represented by the condensers 36.

In using the coil to develop high propulsive forces, it follows that there will be high forces generated within the unit itself, and with this in mind it is also proposed to" construct the unit as illustrated in Figure 5, wherein the unit, generally indicated at-38 has 'a shell'or'casing shading ring are' subjectedto: high forces. due to the. amount ofenergybeing exerted'by theuniton a member passedtherethrough; Such a shell could be'of a laminated or block-filled plastic, a. glass fiber reinforced plastic, plastic bonded glass-fabric, or could'be of metal, either magnetic or non-magnetic, or oftone of'the higher strength" ceramic materials.

Among the uses contemplated for the unit of this invention, in addition to" the deama'gnetizing of work members; such as wat'ch parts and. the like, and its-use as a high power propulsionunit; I also' contemplate utilizing the' unit for moving toys and the like, such as trains, which couldbe moved along a track by arranging a coil unit according to my invention about the track in the manner'of a tunnel;

The coil unit could also beused by utilizing it in connection with certain machine operations,1 such as driving punches, knives, or riveting tools. In certain of the uses referred to above it would be possible to energize the coil with direct current, and in this case th'e'coil would tend to retain a plunger therein and demagnetization or ejection would be accomplished at thev instant of de-energizing the coil.

I alsocontemplate the arrangement of a plurality of coil units, according to my invention, in a circular path, and by selecting the proper frequency of supply current magnetic particles could be driven in a circular path at tremendously high velocities, much in the same manner as electrical particles are now driven in a cyclotron. All articles or particles that are magnetic or which are possessed of a magnetic moment, such as neutron particles, could be driven in this manner.

In further reference to the arrangement of Figure '4, it will. be understood that either a series or parallel pulsion of work members, the members will many times retain an" increment'of magnetism after they have-deft the influence of the 'coil unit:

It will be understood that this invention is susceptible to modification in order to adaptit to difierent usages and conditions, and, accordingly, it is desired to com-- prehend such modifications within this invention as may fall within the scope of theappended claims.

hook-up of the coils couldbe made, and that the impedances illustrated in circuit with the coils are not essential under. all conditions. However, the coils, when arranged end to end as illustrated in Figure 4, should alternate in direction; that is, if the unit at the left has the copper cone part to the left side, the next unit to the right will have the cone part to the right side, and so on for as many coil units as are employed. When the coils are spaced apart it is not necessary'for the coil units to be alternated as to direction;

The same comments as above will obtain when utilizing the arcuate coil of Figure 3. In general, when. the coil units are located in an arcuate path they will be spaced apart therebysimplifying the aligning thereof. In fact, when the coil units are. spacedapart in a circular path straight units couldhe employed with an arcuate guide tube passing therethrough.

In connection with the spacing, of thecoils apart, if it was found, for example, thata coil would. thrust a plunger or member, say, 10 feet and it was desired to I claim:

1.111 an electromagnetic unit; a conical member of electrically conductive non-magnetic material, an electric coil wound around said conical member so that the outer surface of the coil is parallel with theaxis' of'the conical member, said coil extending beyond the apex of said conical member and having an inwardly tapering recess in the end thereof opposite said conical member, a non-magnetic tapered non-conductive member in said recess, and a hollow tube of non-magnetic material extending throughsaid' coil and said conical member on the axis thereof.

2. In an electromagnetic unit; a conical memb'erof electrically conductive non-magnetic materiahan electric coil wound around said conical member so that the outer surface of thecoil isparallel with. the axis of the. conical member, said coil extending .beyond the apex of said" conical member and having'an inwardly tapering recess in.

the end thereof opposite said conical member, a tapered non-magnetic non-conductive member in said recess, and a hollow tube of non-magnetic material extending through said coil and said" members substantially on the axis thereof, said conical member extendingthree-fourths of the way through said coil.

3. In an electromagnetic unit; a conical member of electrically conductive non-magneticmaterial, an electric coil wound around said conical member so that the outer surface of the coil is parallel with the axis of the conical member, saidv coil extending. beyond the apex of said conical member and having an inwardly tapering recess in the end thereof opposite said'conical member, a tapered non-magnetic non-conductive member in said recess, and a hollow tube of non-magnetic material extending through said coil and'said members substantially on the axis'thereof, said tube being curved.

4. In an electromagnetic unit; a conical member of electrically conductive non-magnetic material, an electric coil wound around said conical member so that the'outer surface of the coil is parallel withthe axis of the conical member, said'coil extending beyond the apex of said con-v move the plunger or member for a distance of, about de-magnetizing magnetic members, the speed of ejection should be considerably slower than-would obtain for use of. the unit for propelling projectiles.- This could be accomplishedby introducing a frictionalvdragon; themember so that the de-magnetizing thereof. would be completed by the time. it moved" out. of the field ofinfluence of. the-unit With extremely highz'speed pr0 ical member and having an inwardly tapering recess in the end thereof opposite said conical member, .a tapered non-magnetic.non-conductive member in said recess, and a hollow tube of non-magnetic material extending through said coil and said'members substantially-on the axis thereof, said conical memberextending three-fourths of the. way through said coil, said tube being curved, and the ends of said unit being disposed at angles normal to the axis of the end of the tube adjacent thereto.

5. In an electromagnetic unit; a conical member of electrically conductive non-magneticmaterial, an electric coil wound around said conical member so that the-outer surface-of the coil is parallel with the axis of the conical member, said coil extending beyond the apex of said conical member and having an inwardly tapered recess in the endthereof opposite said conical member, a tapered nonmagnetic non-conductive member in saidrecess overlapping the apex of said conical member and having a central recess in its inner end having an inner wall spaced-from and parallel with the outer surface of said'conical member, and said coil extending into the space between said conical member and said non-magnetic member, there being a passage completely through the unit on the common axis of the coil and saidmembers.

6. In an electromagnetic unit; a conical member of electrically conductive non-magnetic material, an-electric coil:

wound around said conicalmember so'that the outer: stir-- face of the coil is parallel with the axis of the conical member, said coil extending beyond the apex of said conical member and having an inwardly tapering recess in the end thereof opposite said conical member, a tapered non-magnetic non-conductive member in said recess, a hollow tube of non-magnetic material extending through said coil and said conical member on the axis thereof, said conical member extending three-fourths of the way through said coil, and a casing enclosing said unit.

7. In an electromagnetic unit; a conical member of electrically conductive non-magnetic material, an electric coil wound around said conical member so that the outer surface of the coil is parallel with the axis of the conical member, said coil extending beyond the apex of said conical member and having an inwardly tapered recess in the end thereof opposite said conical member, a tapered nonmagnetic non-conductive member in said recess overlapping the apex of said conical member and having a central recess in its inner end having a wall spaced from and parallel with the outer surface of said conical member, said coil extending into the space between said conical member and said non-magnetic member, and a casing enclosing said unit having high tensile strength to support said unit under load.

8. A de-magnetizing unit comprising; an electric solenoid, a conical recess in one end of the solenoid and a conical member of electrically conductive non-magnetic material extending into said recess, a conical recess in the opposite end of said solenoid and an electrically nonconductive and non-magnetic element fitting into said lastmentioned recess, said member and said element having parallel Wall portions spaced apart, said solenoid extend ing into the spaced between said member and element, and a hollow tube of non-magnetic material extending through said member, solenoid, and element on the axis thereof.

9. In combination; a plurality of electromagnetic units arranged end to end, a hollow tube of non-magnetic material extending through said units on the axis thereof, each said unit comprising a conical member of non-magnetic electrically conductive material at one end, an electric coil wound around said member, a non-magnetic electrically non-conductive element in the end of each coil opposite the said conical member, each said nonconductive element being in the general form of a truncated cone with its apex overlapping the apex of said conical member each said non-conductive member having a recess in the apex thereof having an inner Wall spaced from and parallel with the outer wall of said conical member, said coil extending into the space between the said walls, means clamping said units together, and means for supplying electric energy to said units.

10, In combination; a plurality of electromagnetic units arranged end to end, a hollow tube of non-magnetic material extending through said units on the axis thereof, each said unit comprising a conical member of nonmagnetic electrically conductive material at one end, an electric coil wound around said member, a non-magnetic electrically non-conductive element in the end of each coil opposite the said conical member, each said nonconductive element being in the general form of a trunctaed cone with its apex overlapping the apex of said conical member and with a recess in the apex of the non-conductive member and with the inner Wall of said recess being spaced from and parallel with the outer wall of said conical member, said coil extending into the space between the said walls, means clamping said units together, and means for supplying electric energy to said units, said last-mentioned means comprising means for establishing a phase difference between the currents in the respective coils of said units.

11. An electromagnetic ejector unit of the character described comprising; an electric solenoid coil which is substantially cylindrical on the outside and having a tapering electrically conductive non-magnetic member in one end of the coil, said non-magnetic member tapering inwardly from one end of said coil toward the other, a tapered non-magnetic non-conductive member in the other end of the coil, said non-conductive non-magnetic member tapering from the other end of said coil inwardly toward the said one end and overlapping the apex of the said conductive nonmagnetic member, and a tube of nonmagnetic material extending through said solenoid coil.

References Cited in the file of this patent Ser. No. 344,438, Engler (A. P. C.), published May 18, 1943.

Publication: Magnetic Concentration of Iron Ore, Bulletin of Univeristy of Minnesota, pp. 77-80. 

